 ## Angle

The separation of between two straight lines joining at a point is called an angle. When two line segments have a single common point, then an angle is formed at that point.
In the given figure, two line segments AB and BC have a single common point B, then angle ABC is formed at B. It is represented by the symbol ‘’ while writing. The angle can be writen as ABC or CBA.

### Types of Angles

According to the measure of an angle, there are different types of angles as follows:

#### Right angle

An angle whose measure is exactly 90° is called a right angle.
In the given figure, ABC is 90°. So ABC is marked as a Right Angle by a small square at B.

#### Acute Angle

An angle which is less than 90° and more than 0° is called an acute angle.
In the given figure, QPS = 60° which is less than 90°. So QPS is an acute angle.

#### Obtuse Angle

An angle which is less than 180° and more than 90° is called an obtuse angle.
All angles between 90° to 180° are called obtuse angles. In the given figure AOB is more than 90° but less than 180°. i.e. AOB = 135°. So, AOB is an obtuse angle.

#### Straight Angle

An angle of exactly 180° is called a straight angle.
In the given figure, ABC = 180°. So ABC is a straight angle.

#### Reflex Angle

The angle which is less than 360° and more than 180° is called a reflex angle.
In the given figure, XYZ = 220°, which is less than 360° and more than 180°. So XYZ is an reflex angle.

#### Full Turn Angle

The angle which is equal to 360° is called a full turn angle (complete angle).
In the given figure, ABC = 360°. So, ABC is a full turn angle.